1. Field of the Invention
The present invention relates to a toner used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.
2. Discussion of the Related Art
In processes for development of toner, a non-contact development method, in which toner on a development roller is projected onto an electrostatic latent image carrying member with applying an electric field to the toner, has been proposed from the viewpoint of attaining high image quality, contrary to a contact development method in which a development roller is contacted with an electrostatic latent image carrying member such as a photoconductor via a magnetic brush or the like. However, in the non-contact development method, the development efficiency is low, so that reduction of the adhesive force of toner to carrier or toner carrying member and the like is required.
The above-mentioned problem can be solved by lowering the triboelectric charges of toner, but when the triboelectric charges of toner are reduced, toner scattering is likely to be caused. In order to overcome this drawback, various techniques for lowering the van der Waals forces, such as addition of inorganic fine particles having a large particle size with a particle size of from about 20 to about 100 nm (Japanese Patent Laid-Open Nos. Hei 8-15890, Hei 8-227171 and Hei 9-288369), defining adhesive force between toners (Japanese Patent Laid-Open No. Hei 7-13386) and studies on the particle size distribution or the form factor of toner (Japanese Patent Laid-Open Nos. 2000-214629 and Hei 5-142859) have been studied. However, in a long-term durable printing, decrease in image density or generation of void are still observed, so that there is a need to solve these problems.
An object of the present invention is to provide a toner capable of obtaining high-quality fixed image with little decrease in image density and little generation of void even in a long-term durable printing using a non-contact development device.
These and other objects of the present invention will be apparent from the following description.